The present invention relates to novel fluorine containing bis-imide compounds useful as additives to enhance the properties of high performance polymers such as polyimides.
Polyimide resins are used in a wide variety of industrial applications, based on their excellent thermo-oxidative stability, chemical stability, and dimensional stability of molded articles prepared from them. Fluorine-containing polyimides have been found particularly useful for applications requiring low moisture adsorption and high thermal stability.
It is known that the flammability of various material, especially polymeric materials, may be reduced by the incorporation therein of halogen-containing compounds. Various halogenated organic compounds have been useful as fire retardant additives for one type of resin but unsuitable for others because of incompatibility with a particular resin, or inability to withstand particular processing conditions, such as high temperatures. The fluorinated bis-imides of the present invention are particularly useful as additives to polyimide resins to serve as plasticizers and to enhance the already excellent fire retardant properties of such resins.
The incorporation of fluorine containing imide additives into polyimides to enhance the electrical properties, especially to lower the dielectric constant, is shown in U.S. Pat. No. 4,895,972. The patent teaches the incorporation of diamic acid additives, including fluorine containing diamic acids into polyamic acid resins prior to imidization.
U.S. Pat. No. 4,625,832 discloses the incorporation of fluorine containing phthalimides in combination with alkali metal salts, into thermoplastic, branched, aromatic polycarbonates to impart flameproofing properties thereto.